General Unit Testing?

Would this book help me with acquiring a general understanding of unit testing? I use Python, but want to learn “how/why” to write unit tests. I’m starting to do a little Ruby, and find it similiar to Python, so if there is a Ruby-specific book that teaches a lot about unit testing, that might be better suited.

Thanks,
Mike

Looking at the table of contents seems to answer your question:
1 Introduction 1
1.1 Coding with Confidence . . . . . . . . . . . . . . 2
1.2 What Is Unit Testing? . . . . . . . . . . . . . . . 3
1.3 Why Should We Bother with Unit Testing? . . . 4
1.4 What Do We Want to Accomplish? . . . . . . . . 5
1.5 How Do We Do Unit Testing? . . . . . . . . . . . 7
1.6 Excuses for Not Testing . . . . . . . . . . . . . . 9
1.7 Road Map . . . . . . . . . . . . . . . . . . . . . . 14

If you’re looking for a general Unit Testing book without C# details, this might not be the best book for that.

Although the code is written in C#, the code itself is not so enormous and long.
The very book value is in its written part, available for every programmers.